Sustainable sanitation is a sanitation system designed to meet certain criteria and to work well over the long-term. The Sustainable Sanitation Alliance(SuSanA) includes five features (or criteria) in its definition of „sustainable sanitation“, which is an economically and socially acceptable system. 
The purpose of sustainable sanitation in general: to protect human health . However, „sustainable sanitation“ is waiting for all process of the system. This includes methods of collecting, transporting, treating and disposing of waste. Reuse of waste is not essential to the definition. 
Comparison with „improved sanitation“
The Joint Monitoring Program for Water Supply and Sanitation (JMP) of the World Health Organization (WHO ) and UNICEF ( United Nations Children’s Fund ) was responsible for monitoring progress towards the Millennium Development Goal for Drinking Water and Sanitation. For sanitation (toilets that count toward the MDG goals) and „unimproved“ sanitation (toilets that do not count toward the sanitation situation) the MDG goals).
Selon the JMP definition, Improved sanitation facilities include facilities qui are: 
- not shared or public ; and
- which are one of the following toilet types: flush gold for-flush to piped sewer system, septic tank or pit latrine , ventilated improved pit latrine, pit latrine with slab or a composting toilet .
Unimproved sanitation facilities according to the JMP include: 
- flush gold for-flush to elsewhere (waste is flushed to the street, yard or plot, open sewer, ditch, a drainage way or other location)
- pit latrine without slab or open pit;
- bucket toilet ; hanging toilet or hanging latrine, or no facilities or bush or field ( open defecation ).
In certain circumstances „unimpeded“ sanitation facilities may be considered as sustainable. This is because of the sanitation system, of which the toilet is only one part. For example, a pit latrine with a slab can become unsustainable if it is polluted the groundwater or if it is removed from the pit latrine is dumped into the environment. A bucket toilet can become sustainable if the collection, treatment and disposal of waste is taken care of in a safe manner, for example with urine-diverting dry toilets that is used in Haiti. 
Comparison with ecosan
Sustainable sanitation, defined with the five sustainability measures, may be a focus of excreta , because the criterion of „protecting the natural resources“ is only one of several that needs to be aimed towards. In comparison, ecological sanitation (ecosan) has a strong focus on the reuse of waste.
The objective of a sanitation system is to protect and promote human health by providing a clean environment and breaking the cycle of disease. In addition to being economically viable, it should be socially acceptable, and technically and institutionally appropriate, but it should also protect the environment and the natural resources . Selon the Sustainable Sanitation Alliance, When Improving an existing and / or designing a new sanitation system, sustainability criteria related to The Following aspects shoulds be regarded: 
Health aspects include the risk of exposure to pathogens and hazardous substances that may be affected by the treatment of the disease by the health care system. The topic also covers aspects such as hygiene , nutrition and the improvement of the outcome of the application of a certain sanitation system, as well as downstream effects.
Environment and natural resources
Environment and natural resources aspects involve the required energy, water and other natural resources for construction, operation and maintenance of the system, as well as the potential emissions to the environment. It also includes the degree of recycling and reuse of excreta and the effects of these, for the purpose of reusing the wastewater , retaining nutrients and organic material to agriculture, and the protection of other non-renewable resources, for example through the production of renewable energy. (eg biogas or fuel wood).
Technology and operation
Technology and operations can be constructed, operated and monitored using the local human resources (eg local community, technical team of local utility etc.). It also concerns the suitability to achieve an efficient substance flow management from a technical point of view. Moreover, it evaluates the robustness of the system, its vulnerability towards disasters, and the flexibility and adaptability of its technical elements to the existing infrastructure, to demographic and socio-economic developments and climate change .
Finance and economics
Financial and economic issues are related to the capacity of households and communities for sanitation, including the construction, maintenance and depreciation of the system. In addition to the assessment of investment and cost-effectiveness, it is possible to obtain „productive“ sanitation systems, including benefits from the production of recyclables (soil conditioners, fertilizers , energy and reclaimed water ). , employment creation, increased productivity through improved health and the reduction of environmental and public health costs.
Socio-cultural and institutional aspects
Socio-cultural and institutional aspects of socio-cultural acceptance and appropriateness of the system, convenience, system perceptions, gender issues and impacts on human dignity , the contribution to subsistence economies and food security, and legal and institutional aspects.
Planning for sustainable sanitation
Most sanitation systems have been designed with the five aspects in mind, but in practice they are failing far too often because of some of the criteria are not met. Since there is no one-for-all sanitation solution that requires sustainability, it will depend on the existing environment, technical, socio-cultural and economic conditions.
Some of the principles of sustainable water supply and implementation have been proposed by the members of the Water Supply and Sanitation Collaborative Council (the „Bellagio Principles for Sustainable Sanitation“) during its 5th Global Forum in November 2000:
- Human dignity, quality of life and environmental security at household level should be at the center of any sanitation approach.
- In line with good governance principles, decision-making should involve participation of all stakeholders, especially consumers and providers of services.
- Waste should be considered a resource, and its management should be holistic and form part of integrated water resource, nutrient flow and waste management processes.
- The domain in which environmental sanitation problems are determined (household, community, town, district, catchment, city).
These planning guidelines have been revised and are now used in various training courses for urban planners.  
Some examples for improving the present situation in the short-term, from a technology perspective, are listed below:
- Pit latrines could be modified to be-composting latrines ( Arborloos ), thus requiring some reinforcement, made shallow (max 1-1.5 m) and maintained using daily soil additions: the pits would be periodically closed and covered allow for sanitization and composting prior to emptying and reuse in agriculture.
- Simple urinals with separate collector systems could be installed instead of using toilets and pit latrines for urination
- Flush toilets could be modified to less water or reuse graywater. 
- Greywater could provide source-separated from the blackwater from toilets thus simplifying its treatment and providing opportunities for reuse.
- Blackwater from toilets could be held in conservancy tanks instead of open sewage tanks and then emptied and transported to biogas reactors; alternatively the toilets could be connected to biogas reactors.
- Cess (or drainage) pits eg for flushing toilets could be with a safety zone of additional filter material to prevent contamination of ground water.
- Above ground dry toilets with urine diversion could be installed in dry areas lacking water, rocky areas where pits are expensive to dig and areas with high water tables and flooding.
With respect to the other sustainability factors, key areas of attention to the creation of an enabling environment, market development and capacity development.
- Bill and Melinda Gates Foundation – active in the area of sustainable sanitation research and implementation
- Jump up^ BMGF (2015). Building demand for sanitation – a 2015 portfolio update and overview- Water, sanitation, and hygiene strategy, June 2015. Bill & Melinda Gates Foundation, Seattle, Washington, USA
- ^ Jump up to:a b SuSanA (2008). Towards more sustainable sanitation solutions – SuSanA Vision Document . Sustainable Sanitation Alliance (SuSanA)
- Jump up^ Tilley, E., Ulrich, L., Luthi, C., Reymond, Ph. And Zurbrügg, C. (2014). Compendium of Sanitation Systems and Technologies. 2nd Revised Edition. Swiss Federal Institute of Aquatic Science and Technology (Eawag), Duebendorf, Switzerland
- ^ Jump up to:a b „WHO / UNICEF Joint Monitoring Program: wat / san categories“ . www.wssinfo.org . Retrieved 2017-03-21 .
- Jump up^ Russel, K. (2013). Mobile sanitation services for dense urban slums- Various materials are results from research grant. Stanford University, USA
- Jump up^ IWA (2005). Sanitation 21 – Simple approaches to complex sanitation. International Water Association (IWA), London, UK
- Jump up^ Lüthi, C., Panesar, A. Schütze, T. Norström, A. McConville, J. Parkinson, J. Saywell, D. Ingle, R. (2011). Sustainable sanitation in cities: a framework for action. Sustainable Sanitation Alliance (SuSanA), Papiroz Publishing House, International Forum on Urbanism (IFoU),ISBN 978-90-814088-4-4
- Jump up^ Duttle, Marsha (January 1990). „NM State gray water advice“ . New Mexico State University . Retrieved 23 January 2010 .